JPS6345629B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention uses a fluidized bed reactor with a spray nozzle to process (chemical reaction, drying, etc.) a liquid (including solution and slurry) or gaseous substance and convert it into a solid substance. The present invention relates to a nozzle for spraying and supplying the substance in an apparatus for obtaining the substance. Uranium and/or plutonium, originating from, for example, spent nuclear fuel reprocessing plants, is usually purified in the form of uranyl nitrate (UNH) or plutonium nitrate, and then converted to UO ₃ or/and PuO ₂ , with respect to uranium. is further supplemented with UO ₂ (uranium dioxide) or UF ₆ as required.
(Uranium hexafluoride), but this UNH
A fluidized bed reactor with a spray nozzle is used for the conversion of UO 3 to UO ₃ . Reconversion of UF ₆ in the nuclear fuel cycle (including reconversion of waste UF ₆ ) When originating from a factory, etc., UF ₆ is H ₂ O
Hydrolyzed by UO ₂ F ₂ (uranyl fluoride)
converted into. A fluidized bed reactor having a spray nozzle can be used as a reactor for this hydrolysis of UF ₆ . At plants that process liquid radioactive waste discharged from spent nuclear fuel handling facilities, solutions containing salts of various radioactive wastes are processed, and the salts of the materials are dried or thermally decomposed to form a solid state. A fluidized bed reactor with a spray nozzle is used as a drying or pyrolysis reactor for the conversion into substances. In addition, a solution of a certain substance, such as a boric acid aqueous solution or an aluminum nitrate aqueous solution, can be sprayed or
In the process of drying (including thermal decomposition) to obtain granular boric acid, aluminum oxide, etc., a fluidized bed reactor having a spray nozzle can be effectively used as a processing device for these. The present invention is directed to a fluidizing system having a spray nozzle for processing (chemical reaction, drying, etc.) a liquid (including solution and slurry) or gaseous substance to obtain a solid substance. This relates to a nozzle that sprays and supplies the substance in a bed reactor, and its feature is that a guide tube is attached to the tip of the nozzle that supplies the raw material to the fluidized bed. The present invention is generally applicable to a fluidized bed reactor having a spray nozzle for processing a liquid or gaseous substance to obtain a solid substance.
The present invention will be explained below using a fluidized bed reactor for thermal decomposition of UNH (uranyl nitrate) (so-called denitrification) as an example. Pyrolysis of UNH by fluidized bed is the raw material
The conventional method is to blow UNH together with atomized gas into a fluidized bed reactor through a spray nozzle, and heat it from the outside to thermally decompose it to produce UO ₃ powder. Since this thermal decomposition reaction of UNH is a rapid endothermic reaction, the temperature near the tip of the spray nozzle drops considerably, causing undecomposed UNH, condensed H ₂ O, UO ₃ powder, etc. to adhere to the tip of the spray nozzle. , often gradually growing into lumps. Once these lumps have grown to a certain extent, they fall from the tip of the spray nozzle due to the intense agitation within the fluidized bed. This lump is often generated in a cylindrical shape from the tip of the nozzle, as will be explained later with reference to the drawings. Due to the intense agitation in the fluidized bed, some of the lumps produced in this way fall off, and small ones are discharged from the UO ₃ powder extraction pipe together with the generated UO ₃ powder, but large ones remains in the fluidized bed. The size of the remaining lumps varies depending on the operating conditions of the fluidized bed or the design conditions of the equipment, but in the case of a fluidized bed reactor for denitrification in a spent nuclear fuel reprocessing plant, etc., it is generated without disassembling the equipment. Designing an apparatus that can completely discharge lumps is difficult due to issues such as criticality and the diameter of the apparatus. In addition, in fluidized bed reactors, operating conditions are often limited in order to obtain a stable fluidized state or to obtain a desired product. It is extremely difficult to set the operating conditions to such an extent that the particles will completely fall off, and the formed lumps often grow without falling off. When the generated lumps grow without falling off the surface of the spray nozzle, they gradually come to cover the entire surface of the spray nozzle, and eventually cover the outlet of the spray body. In this situation, the spray nozzle becomes blocked, making it impossible to supply a certain amount of raw material (UNH). Disturbances in the supply of UNH make it difficult to control the temperature of the equipment, making it virtually difficult to maintain equipment operation and obtain the desired product. A method for completely preventing the generation of these lumps has not yet been perfected. If a lump grows and the nozzle becomes clogged, or as a measure to prevent blockage, use a cleaning needle to mechanically punch a hole in the lump at the tip of the nozzle (this operation may cause the lump to fall from the spray nozzle surface). ) method, or a method of cleaning the spray nozzle with hot water or acid stored in a pressurized container, etc., but the former method has the disadvantage that the needle is often damaged because the needle is moved back and forth mechanically. In addition, when the needle is returned, the UO ₃ powder in the fluidized bed is often drawn into the supply path of the spray body (liquid supply path in the spray nozzle), creating a more firmly blocked state, and furthermore, When the needle is in operation, the supply to the fluidized bed is stopped, which adversely affects the operation management of the device, so it is practically impossible to employ this method in actual devices. The latter method was previously disclosed by the applicant (Japanese Patent Laid-Open No. 19052/1983). In this case, the blockage of the spray nozzle can be released or prevented by injecting and cleaning pressurized liquid from the liquid supply path of the spray nozzle each time or periodically before the blockage occurs. Even if the spray nozzle becomes clogged, this method of spraying and cleaning the pressurized liquid makes it possible to reopen the raw material liquid supply path, release the clogged state, and maintain a stable spray state (stable flow state). ) can be maintained. However, although this method is effective in eliminating blockages, it cannot eliminate the blockage phenomenon. Many of the lumps that have grown to the point of causing blockage are relatively large, and even if they can be removed from the tip of the spray nozzle, they will gradually accumulate in the fluidized bed and require long-term operation. In some cases, the flow characteristics may be adversely affected and the operation may be shut down. If these lumps are relatively small in size, they can be extracted simultaneously with the product from a pipe for discharging the product from the fluidized bed (usually with overflow and underflow). For example, in the case of UNH's pyrolysis fluidized bed reactor,
Considering the operating conditions, etc., it is possible to extract any lumps up to about 20 mm from the overflow. In addition, if the diameter of the fluidized bed is sufficiently large, the diameter of the underflow (extraction pipe) installed at the bottom of the fluidized bed can be made to allow the passage of the lumps, thereby making it possible to extract the lumps that fit into the diameter. It is possible. However, when dealing with enriched uranium or plutonium such as reprocessing spent nuclear fuel (in this case, the diameter of the fluidized bed is limited due to criticality control), underflow (extraction) is impossible. Measures have been taken to prevent lumps from entering the extraction pipe by installing a screen on the top of the tube (Japanese Patent Application Laid-open No. 7529/1983), but in this case, lumps are trapped inside the fluidized bed. It remains on the rectifier plate and is not a fundamental solution. Even if the diameter of the underflow (extraction tube) can be made sufficiently large, extraction of powder from the fluidized bed through the underflow will cause fluctuations in the height of the fluidized bed because the powder and lumps that form the fluidized bed will be extruded at the same time. This is undesirable from an operational management perspective. If the lumps are to be removed from the fluidized bed after the operation has been stopped, it is necessary to disassemble the device, so equipment must be provided to prevent UO ₃ powder from scattering during disassembly. The explanation regarding this lump formation is given as a typical example.
The explanation uses the thermal decomposition reaction of UNH as an example, but it is not limited to the thermal decomposition reaction of UNH, but in general.
This is a common problem that occurs when a fluidized bed having a spray nozzle is used to process a liquid or gaseous substance to obtain a solid substance, and when the substance is sprayed and supplied. A certain amount of lumps exist during operation in the fluidized bed equipment currently in practical use, but in principle it is desirable that these lumps be completely removed. Based on our experience in operating fluidized bed equipment for decomposition reactions, etc., we have found that although this depends on the size of the equipment, operating conditions, physical properties of the lumps, etc., even if the amount of production (accumulation) is below a certain level, In particular, it has been found that the fluidized bed apparatus can be operated without adversely affecting the flow characteristics. The present inventors have obtained such knowledge and the knowledge obtained from UNH's operating experience of fluidized bed equipment for thermal decomposition reactions, etc., namely, that the agglomerates on the surface of the spray nozzle usually grow in a cylindrical shape, and that the agglomerates The present invention was achieved by paying attention to the fact that when the spray nozzle is attached in a cylindrical shape, the spray nozzle is less likely to be clogged and operation is stable. That is, the present invention uses a fluidized bed having a spray nozzle to process (chemical reaction, drying, etc.) a liquid (including solution and slurry) or gaseous substance to obtain a solid substance. In the apparatus, there is provided a spray nozzle characterized in that a guide tube is attached to the tip of the nozzle for spraying and supplying the substance. According to the present invention, in an apparatus for processing a liquid substance or a gaseous substance to obtain a solid substance using a fluidized bed reactor having a spray nozzle, a nozzle for spraying and supplying the substance is generally used. (Atomizing nozzle) If a lump is formed on the tip of the spray nozzle due to the adhesion of the substance and/or its product or a powder substance forming a fluidized bed, it may cause blockage of the nozzle, or the operation due to the accumulation of lumps may occur. Although this may hinder operation, etc., it is possible to provide a spray nozzle that solves these problems and enables long-term operation of a fluidized bed reactor. Next, the present invention will be specifically described with reference to the drawings. Figures 1 and 2 illustrate the situation of lump formation in conventional nozzles. In FIGS. 1 and 2, 5 is the wall of the reactor, 1 is an injection nozzle, and 4 is a supply pipe for the liquid to be treated (in this case, a solution of UNH). In the case of UNH pyrolysis, the produced lumps are UO ₃ produced by pyrolysis and drying of UNH and formed fluidized bed.
It consists of _UO3 particles, etc., and its formation mechanism is thought to be as follows. That is, spray nozzle 1 (4
is the spray body 3 sprayed from the UNH solution supply pipe)
(in this case UNH and H ₂ O) is repelled by the fluidized bed forming material (in this case UO ₃ powder) and deposits on the surface of the spray nozzle. As mentioned above, the temperature of the surface of the spray nozzle is lowered due to heat absorption due to the thermal decomposition reaction of UNH and is below the solidification temperature of UNH, so UNH is deposited on that part (the surface of the spray nozzle). This UNH receives heat from the outside and thermally decomposes and changes into UO ₃ to form a lump 2. Further, near the outer periphery of the spray nozzle indicated by A in FIG. 2, a vortex is generated due to the interaction between the supply of the spray body to the fluidized bed and the flow of fluidizing gas and the like. UO ₃ forming a fluidized bed in this vortex
A portion of the powder is entrapped and adheres to the wet spray nozzle surface or the surface of the undried agglomerate, forming part of a new agglomerate and growing. By providing a guide cylinder at the tip of the nozzle according to the present invention, the spray nozzle does not become clogged and stable operation of the fluidized bed reactor becomes possible. The size of the lumps is reduced and the physical properties make them easy to fluidize, so that they are easily discharged from overflow and do not accumulate in the fluidized bed and have an adverse effect on operation management. This produces effects such as This fact has been grasped entirely empirically, and there is currently no theoretical explanation as to why such an effect is obtained, but the observation results of the generated lumps and their cross sections It can be considered as follows. In other words, in a typical (conventional) spray nozzle, the lumps adhering to the spray nozzle surface first grow (develop) from the outer periphery of the nozzle shown at A in Figure 2 in the direction of the points shown at B and C in the same figure. )do. During this growth,
Some of the lumps fall off due to the intense agitation in the fluidized bed, but the lumps that do not fall off during the course cover almost the entire area of the spray nozzle surface (A in Figure 1).
As the growth progresses further, it also covers the course of the atomized material sprayed from the nozzle in the fluidized bed. This state is a state in which blockage occurs, and at this point, if the force applied to the agglomerate by the spray pressure of the spray body overcomes the adhesion force of the agglomerate to the spray nozzle surface, the agglomerate falls off from the spray nozzle surface. The method previously disclosed by the applicant for preventing or releasing nozzle blockages by spraying and cleaning pressurized liquid not only dissolves lumps, but also applies this principle to eliminate inconveniences caused by spray nozzle blockages. It is something that will be resolved. ) In such cases, with conventional spray nozzles, the contact (adhesion) area between the agglomerates and the spray nozzle surface is large and the adhesion is strong, making it difficult for the agglomerates to fall off from the nozzle surface. The forces that agglomerates receive as they fall off during growth are mainly the kinetic force of the particles due to agitation in the fluidized bed and the force applied by vibration of the device, and the agglomerates that do not fall off midway through the process reach the vicinity of the spray passage of the nozzle. Since the particles grow over almost the entire surface of the spray nozzle, it takes a long time for the particles to adhere (and grow), and the area of contact and adhesion between the particles and the nozzle surface becomes large, increasing the adhesion force. As a result, the lumps are difficult to fall off, and since drying progresses during that time, the adhesion becomes stronger and stronger. In contrast, in the present invention, as shown in FIG. 3, since the lumps 2 adhere and grow on the tip 6a of the guide tube 6 attached to the tip of the spray nozzle, the contact (adhesion) area of the lumps is small. Since the adhesion is weak, lumps tend to fall off. The lump is in the process of growing (the stage where it does not grow large)
At this time, as shown in FIG. 4, a force is applied by the spray body 3 which has been injected and spread to some extent. At this point, the attached lumps have not yet become very strong, and the attached area is small (and therefore the adhesion force is small),
It easily falls off from the tip of the guide tube of the spray nozzle. Due to this effect, if the present invention is adopted,
Blockage of the spray nozzle no longer occurs and the size of the agglomerates produced is reduced. The lumps that have become smaller are easily fluidized as described above and are discharged from the overflow.
As a result, troubles such as disruptions in operation management due to spray nozzle blockage and operation stoppages due to the accumulation of lumps, which were observed in fluidized bed reactors using conventional spray nozzles, are eliminated. It becomes possible to operate and operate a fluidized bed reactor having a stable system for a long period of time. FIG. 5 is a schematic vertical sectional view of a fluidized bed reactor for UNH thermal decomposition reaction as an example to which the spray nozzle of the present invention is applied. The device has a tower shape and is assembled from several parts, with an inlet port 1 for fluidizing gas at the bottom.
7. Wind box 8 for the pool of the gas, rectifying plate 9 for the gas, temperature measuring device 12, underflow extraction pipe 13, nozzle 1 for introducing reaction gas or liquid, overflow outlet pipe 12,
Operation tube 18, heating means 16, temperature measuring device 1
5, 15', a filter 10, a gas outlet 11, etc. This is completely known and there is no need to explain it in further detail. The operation of this apparatus will be explained using a thermal decomposition reaction of UNH as a representative example. As shown in FIG. 5, UNH solution u, which is a raw material liquid, is blown into a fluidized bed 7 through a spray nozzle 1 together with a spray gas p, and is converted into UO ₃ by thermal decomposition. Fluidized bed 7
is made up of a powder of UO ₃ particles produced, which also includes some of the aforementioned agglomerates. The fluidizing gas f for fluidizing the UO ₃ particles is inlet 17
It is introduced from the wind box 8 to the rectifying plate 9.
into the fluidized bed. The gas produced by the thermal decomposition reaction, the fluidizing gas, and the atomizing gas are separated from the fine UO ₃ particles that accompany them in the solid-gas separation filter 10 installed at the top of the fluidized bed reactor, and then converted into gas. The gas is sent from the discharge port 11 to the waste gas treatment system. FIG. 6 is an enlarged sectional view of a spray nozzle equipped with a guide tube according to the present invention. A shows a longitudinal sectional view, and b shows a cross section of the guide tube. The nozzle 1 is a known spray nozzle, and the guide tube 6 according to the present invention can be easily attached to the spray nozzle by a conventional method such as welding. In order to carry out the present invention in the simplest manner, a tube as shown in FIG. 6 may be used, but the shape of the guide tube is not limited to that shown in FIG. Something like this is also effective. The one shown in FIG. 7 is cut diagonally so that its tip opens upward. The one shown in FIG. 8 has a square cross section. Other shapes are also valid. According to the method of the present invention, a fluidized bed reactor having a spray nozzle is used to process (chemical reaction, drying, etc.) a liquid (including solution and slurry) or gaseous substance into a solid substance. The fluidized bed reactor can be operated and operated stably for a long period of time without causing any adverse effects on the fluidized bed operation due to blockage of the nozzle that feeds and sprays the substance and accumulation of lumps generated during the reaction process. I can do that. When carrying out the present invention, the length of the guide tube attached to the tip of the spray nozzle is determined based on the supply amount of raw material liquid, etc., the amount of spraying gas, the specifications of the nozzle used, the supply pressure of raw material liquid, etc. Depending on the operating conditions, it can be easily designed and manufactured by those skilled in the art based on common knowledge. Next, the present invention will be explained with reference to Examples and Comparative Examples, but these are merely illustrative and the technical scope of the present invention is not limited thereto. In addition, in these examples, the linear velocity of the fluidizing gas near the raw material introduction point is simply the fluidizing gas velocity, the raw material introduction speed is the processing speed, and the atomization gas/raw material liquid volume ratio is the atomization condition ( A/L). Comparative Example 1 UO ₃ was obtained by thermal decomposition reaction of UNH using a fluidized bed reactor with an inner diameter of 6 inches (15.24 cm).
The device is an overflow discharge type, and the height of the fluidized bed is 90cm.
It was hot. The operating conditions are as follows. Reaction temperature 285℃ UNH solution concentration 1200g-U/Treatment speed 10Kg-U/hr Fluidizing gas speed 30cm/s Atomization conditions (A/L) 300 Spray nozzle Commercial product (normal nozzle, no guide tube) Above conditions Although the system was operated for 12 hours, the spray nozzle frequently became clogged, and UNH supply sometimes stopped due to increased spray pressure. Each time, the operation was continued while spraying and cleaning the spray nozzle with pressurized hot nitric acid (hereinafter simply referred to as cleaning). During operation of the device, the discharge of a maximum of about 20 mm of lumps from the overflow was observed. Furthermore, after the completion of the operation, the particle size distribution of the lumps remaining in the fluidized bed was examined and found to be as follows.

[Table] Example 1 Using the same equipment as in Comparative Example 1, UNH was pyrolyzed to obtain UO ₃ . The operating conditions are the same as in Comparative Example 1 except for the spray nozzle. Reaction temperature 285℃ UNH solution concentration 1200g-U/Processing speed 10Kg-U/hr Fluidizing gas velocity 30cm/s Atomization conditions (A/L) 300 Spray nozzle A commercially available product has an induction tube with the structure shown in Figure 6 at its tip. The spray nozzle was operated for 12 hours under the conditions that the length of the guide tube was 15 mm and the inner diameter of the guide tube was 12 mmφ, but there was no blockage of the spray nozzle and stable operation was possible. During operation, as in Comparative Example 1, a maximum of about 14 mm of lumps was observed to be discharged from the overflow. Furthermore, the particle size distribution of the lumps remaining in the fluidized bed after the end of the operation was as follows.

[Table] Example 2 Using the same equipment as in Comparative Example 1 and under the same operating conditions as in Example 1, UNH was pyrolyzed to obtain UO ₃ . However, the length of the guide tube attached to the tip of the spray nozzle is
I used a 10mm one. Operation was carried out for 12 hours under these conditions, but as in Example 1, there was no blockage of the spray nozzle and the operation was stable.
No lumps exceeding a maximum size of 16 mm x 16 mm were observed. Example 3 Using the same equipment as in Comparative Example 1 and under the same operating conditions as in Example 1, UNH was pyrolyzed to yield UO ₃ . However, the guide tube attached to the tip of the spray nozzle was the one shown in Figure 7. (The length of the guide tube is at the longest part.
(20 mm, 10 mm at the shortest point) Operation was carried out for 12 hours under these conditions, but as in Example 1, the spray nozzle was not clogged and the operation was stable.
No lumps exceeding a maximum size of 16 mm x 16 mm were observed. Example 4 UNH was pyrolyzed using the same equipment as in Comparative Example 1 and under the same operating conditions as in Example 1. However, the guide tube attached to the tip of the spray nozzle had a rectangular cross section with one side of 12 mm (the shape shown in Figure 8) and a length of 15 mm. Operation was carried out for 12 hours under these conditions, and the results were almost the same as in Example 1. Comparative Example 2 UNH was thermally decomposed using the same equipment and under the same conditions as Comparative Example 1 to obtain UO ₃ . The total operating time was approximately 150 hours, but the spray nozzle often became clogged and cleaning was performed during operation. From around 130 hours of operation, a difference began to appear in the temperature measurements at the top and bottom of the fluidized bed (near the rectifier plate), and signs that the mixing condition in the fluidized bed was deteriorating were observed. After 150 hours of operation, the flow characteristics deteriorated significantly, the supply of UNH from the spray nozzle became unstable, and constant operational control (temperature maintenance) was no longer possible, so operation was stopped. After the operation was completed, the UO ₃ powder inside was extracted, but there were many lumps and the extraction operation was extremely difficult. In the fluidized bed, even after the UO ₃ powder is extracted, lumps remain on the rectifying plate.
When the accumulated state of the remaining agglomerates was observed, agglomerate particles with large diameters (approximately 20 mm or more) were accumulated on the current plate to a thickness of about 5 cm (1.95 Kg-UO ₃ ). The particle size distribution of the accumulated lumps was investigated and found to be as follows.

[Table] Example 5 Using the same equipment as Comparative Example 1, under the operating conditions of Example 1.
UNH was pyrolyzed to obtain _UO3 . After approximately 180 hours of operation, there was almost no clogging of the spray nozzle, and stable operation was possible. No problems were observed after 180 hours of continuous operation, and continuous operation was still possible. During operation, the discharge of lumps up to approximately 20 mm in size from the overflow was observed. After the operation was completed, the UO ₃ powder inside was removed smoothly, and the amount of lumps remaining in the fluidized bed equipment after the UO ₃ powder was removed was only about 0.35Kg-UO ₃ , and no lumps larger than 20 mm were observed. Ta. The particle size distribution of the remaining lumps was investigated and found to be as follows.

[Table] Comparative Example 3 UF ₆ was converted to UO ₂ F ₂ by hydrolysis reaction using a fluidized bed reactor with an inner diameter of 3 inches (7.62 cm).
I got it. The apparatus was of an overflow discharge type, the height of the fluidized bed was 40 cm, and the operating conditions were as follows. Reaction temperature 600℃ Processing speed 5Kg-UF ₆ /hr Fluidizing gas speed 35cm/s (H ₂ O / UF ₆ ) molar ratio 5.5 Spray nozzle Commercially available product (nozzle with the same specifications as that used in Comparative Example 1) Although operation was carried out for 6 hours under these conditions, the spray nozzle frequently became clogged, and the operation was unstable due to increases in spray pressure, etc. After the operation was completed, there were 5 lumps remaining in the fluidized bed, and the largest one was 32 mm x 18 mm x 16 mm. Example 6 The same equipment as Comparative Example 3, the same conditions, and only the spray nozzle with the same specifications as that used in Example 1.
Hydrolysis of UF ₆ was performed instead of pyrolysis of UNH. Although operation was carried out for 12 hours under the above conditions, no blockage of the spray nozzle occurred and stable operation could be maintained. No problems were observed even after 12 hours of operation, and continuous operation for an even longer period of time was possible. After the operation ended, no lumps larger than 16 mm were observed remaining in the fluidized bed. Comparative Example 4 Aluminum oxide was obtained by thermally decomposing an aluminum nitrate solution using a fluidized bed reactor with an inner diameter of 4 inches (10.16 cm). The equipment is an overflow discharge type, and the height of the fluidized bed is 50 cm. The operating conditions are as follows. Reaction temperature 400℃ Aluminum nitrate concentration 2mol% Treatment speed 0.8Kg-Al ₂ O ₃ /hr Fluidization gas speed 30cm/s Atomization conditions (A/L) 400 Spray nozzle Nozzle with the same specifications as that used in Comparative Example 3 Although operation was carried out for 6 hours under the above conditions, the spray nozzle frequently became clogged, and the operation was unstable due to increases in spray pressure, etc. Example 7 An aluminum nitrate solution was thermally decomposed using the same equipment and under the same conditions as in Comparative Example 4, except for the spray nozzle that had the same specification as that used in Example 1. After 12 hours of operation, the spray nozzle did not become clogged and stable operation was maintained. No problems were observed even after 12 hours of operation, and continuous operation for an even longer period of time was possible.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view schematically showing the shape of lumps generated on the surface of a spray nozzle due to thermal decomposition of uranyl nitrate or the like. Figure 2 shows conventional (commercially available)
FIG. 2 is an explanatory diagram showing each point on the spray nozzle surface to explain the process of growth of lumps in the spray nozzle. FIG. 3 is a cross-sectional view schematically showing the state of adhesion of lumps generated at the tip of the guide tube of a spray nozzle to which the guide tube is attached according to the present invention. FIG. 4 is a sectional view schematically showing the spread state of the spray at the tip of the guide tube of the spray nozzle to which the guide tube is attached according to the present invention.
FIG. 5 is a sectional view of a basic UNH pyrolysis fluidized bed reactor to which the present invention is applied. FIG. 6A is a sectional view of a basic spray nozzle and a guide tube according to the present invention attached to its tip, and FIG. 6B is a front view of the guide tube. FIG. 7 is a front view and a side view of another example of the guide tube attached to the tip of a spray nozzle that can be used in the present invention, and FIG. 8 is a front view and a side view of another example of the guide tube. In these figures, 200... fluidized bed reactor, 5... vessel wall of the reactor, 1... feed spray nozzle for untreated substance, 6... guide tube.

Claims (1)

[Claims] 1. A fluidized bed in which a liquid (including solution and slurry) substance or gaseous substance is processed (chemical reaction, drying, etc.) to obtain a solid substance in a fluidized bed state. 1. A spray nozzle for spraying and supplying a substance to be treated for use in a reaction device, the spray nozzle having a guide cylinder attached to its tip, the base end of which is fixed to the tip of the nozzle. 2. The spray nozzle according to claim 1, wherein the guide tube has a simple cylindrical shape. 3. The spray nozzle according to claim 2, wherein the tip of the guide tube is cut diagonally so as to open upward. 4. The spray nozzle according to claim 1, wherein the guide tube has a square cross section.